This invention relates to thrombin inhibitors which are useful anticoagulants in humans and animals. In particular it relates to derivatives of the dipeptide L-Proline-L-Arginine aldehyde having high antithrombotic activity.
Thrombin inhibition is currently achieved by the administration of heparins and coumarins. The mechanism by which these agents act has been much studied. Heparins are only administerable parenterally and levels must be carefully monitored. Coumarins act by blocking or inhibiting the formation of prothrombin and require some time to achieve maximum effectiveness.
Although both the heparins and the coumarins are effective anticoagulants there exists a need for antithrombin agents which act quickly to prevent clot formation and which do not interfere with plasmin action in dissolving existing clots.